The vapor has no foreign particles, and is therefore able to lose large amounts of energy before forming around something.

This layer is responsible for cleansing the eye and washing away foreign particles.

Some of the T cells directly kill foreign particles.

It may also have the function of transporting foreign particles.

When foreign particles enter the body, the antigens either let them through or recognize them as threats and attack.

Its function may be to keep insects and foreign particles from entering the nasal cavity.

When this system is not working properly, the body's defenses cannot fight off foreign particles.

"My mistake; just a foreign particle on my contact lenses."

Its main function is to keep foreign or unwanted particles from entering the lungs through the nasal cavity.

Pick over the lentils and discard any foreign particles.